Fluid control is a critical aspect of various industrial processes, from chemical manufacturing to water treatment. In these applications, precise control over the flow of liquids or gases is often achieved using valves. One type of valve that has gained popularity due to its reliability and efficiency is the pilot operated diaphragm valve. In this article, we will delve into the essential considerations for sizing and flow control when using pilot operated diaphragm valves, highlighting their advantages in fluid handling. Additionally, we will introduce Aira Euro Automation, a leading company in the valve manufacturing sector, known for its innovative solutions and high-quality products.

Understanding Pilot Operated Diaphragm Valves

Pilot operated diaphragm valves are widely used for controlling the flow of fluids in both high and low-pressure applications. They consist of a main valve and a pilot valve. The main valve is typically a diaphragm valve that controls the flow of fluid, while the pilot valve is a smaller valve that controls the opening and closing of the main valve. This design allows for precise control over the flow rate and pressure of the fluid passing through the valve.

The diaphragm in the main valve is a flexible membrane that responds to changes in pressure. When the pilot valve opens, it allows control pressure to act on the diaphragm, causing it to move and open the main valve. Conversely, when the pilot valve closes, the control pressure is released, and the diaphragm closes the main valve. This mechanism enables smooth and accurate modulation of the fluid flow.

Sizing Considerations for Pilot Operated Diaphragm Valves

Proper sizing of pilot operated diaphragm valve is essential to ensure optimal performance and efficiency in fluid control systems. Undersizing or oversizing a valve can lead to issues such as unstable control, excessive wear and tear, and reduced service life. When sizing a valve, several factors should be taken into account:

  • Flow Rate: Determining the required flow rate is crucial for selecting the right valve size. The valve must be able to handle the maximum expected flow rate without causing excessive pressure drop or flow turbulence.
  • Pressure Drop: Pressure drop across the valve is a critical consideration, especially in systems with limited available pressure. A well-sized valve will have a pressure drop within acceptable limits, minimizing energy consumption and maintaining system stability.
  • Operating Pressure: Understanding the operating pressure range of the system is important for selecting a valve that can withstand the pressure without leakage or failure.
  • Fluid Characteristics: The type of fluid being handled, its viscosity, corrosiveness, and temperature can all impact the choice of valve material and design.
  • Cavitation and Noise: In applications where cavitation (the formation of vapor bubbles) or noise are concerns, valve sizing can help mitigate these issues by ensuring the valve operates within safe pressure and velocity limits.

Flow Control Considerations

Pilot operated diaphragm valves excel in applications where precise flow control is necessary. Their design allows for proportional control, meaning that the valve can accurately maintain a desired flow rate regardless of fluctuations in upstream pressure. This is particularly beneficial in processes where maintaining consistent conditions is crucial for product quality or system integrity.

One of the key advantages of pilot operated diaphragm valves is their ability to operate at lower pressure differentials compared to other valve types. This feature not only reduces energy consumption but also extends the life of the valve by minimizing wear on internal components. The gradual opening and closing of the diaphragm also contribute to smoother control and reduced wear and tear.

Aira Euro Automation: Innovating Fluid Control Solutions

When it comes to reliable and high-performance valves, Aira Euro Automation stands out as a leader in the industry. With a strong commitment to innovation and quality, Aira Euro Automation has been providing cutting-edge valve solutions to various sectors, including oil and gas, chemical, pharmaceutical, and water treatment.

Founded with a vision to revolutionize fluid control, Aira Euro Automation offers a comprehensive range of valves, including pilot operated diaphragm valves, that are designed to meet the diverse needs of modern industries. The company’s valves are known for their precision, durability, and efficiency, making them the preferred choice for critical applications where accurate flow control is paramount.


Pilot operated diaphragm valves play a crucial role in optimizing fluid handling efficiency across a wide range of industrial processes. Proper sizing and flow control considerations are essential to harness their full potential and ensure seamless operation. With their ability to provide accurate and proportional control, these valves contribute to improved process quality, reduced energy consumption, and extended valve life.

Aira Euro Automation, a prominent player in the valve manufacturing sector, continues to be at the forefront of delivering innovative fluid control solutions. Their commitment to excellence and customer satisfaction makes them a reliable partner for industries seeking high-quality valves tailored to their specific requirements. As industries continue to evolve, the synergy between advanced valve technology and precise flow control will undoubtedly shape more efficient and sustainable processes.